At the École Polytechnique Fédérale deLausanne (EPFL) in Switzerland, professor Rainer Beck and his research groupare studying chemical reactions betweengas molecules and solid surfaces.
Processes in surface chemistry such as
heterogeneous catalysis and chemical
vapor deposition are important in many in-
dustrial implementations, such as catalytic
conversion in automobiles and semicon-
ductor growth in the electronics industry.
In Beck’s laboratory, researchers arestudying the effects of laser excitation insuch processes. The results of these experiments provide stringent tests for theoretical models of gas-surface chemistry.
The group is currently using an Acu-
light Argos CW OPO to study the reaction
of methane with a nickel catalyst. The
OPO prepares a beam of methane mole-
cules in a specific excited state. To pre-
serve the molecules in this state, the
preparation is performed under collision-
free conditions in a molecular beam (Fig-
ure 4), whereby the absorption feature is
reduced to less than a few megahertz in
width. The high spectral resolution and
Figure 5. (left) This graph shows methane spectra calculated from a Hitran database. The arrow indicates the 13C peak used for measurements. (right) This chartillustrates the photoacoustic spectra of laboratory air. Courtesy of Radboud University.
Mid-Infrared Tunable Lasers